Objective: The combined serotonin-norepinephrine reuptake
inhibitor, venlafaxine, has demonstrated better short-term efficacy than
selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine in pooled
analyses. This study aimed to compare venlafaxine and fluoxetine treatment in
the long-term outcome measure, time to rehospitalization, in patients with
major depressive disorder. Other clinical factors that may influence time to
rehospitalization were also explored.

Method: Han Chinese patients were admitted to the depression
inpatient unit of a major psychiatric center in Taiwan from January 1, 2002, to
December 31, 2003. Patients with major depressive disorder (DSM-IV) who showed
favorable treatment response to venlafaxine (mean ± SD dose = 116.5 ± 42.5
mg/day; N = 122) or fluoxetine (mean ± SD dose =25.1 ± 9.0 mg/day; N = 80)
during hospitalization were followed up for 1 year after discharge under
naturalistic conditions. The 2 treatment groups were similar in demographic and
clinical characteristics: sex, age, age at illness onset, comorbid anxiety
disorders, personality disorders, nicotine dependence, psychotic features,
adjunctive antipsychotics use, duration of index hospitalization, and number of
previous hospitalizations. Time to rehospitalization was measured by the
Kaplan-Meier method. Possible associations of rehospitalization with other
covariates were analyzed using the Cox proportional hazards regression model.

Results: No significant difference for the time to
rehospitalization was found between the 2 groups by the log-rank test. The
number of previous admissions (hazard ratio = 1.331, 95% CI = 1.153 to 1.538, p
= .000), but not other factors, increased the risk of rehospitalization.

Conclusion: The findings suggest that venlafaxine and
fluoxetine have similar effects on time to rehospitalization in patients with
major depressive disorder. The relatively low dose of venlafaxine may have
contributed to the negative finding. Previous hospitalization history may raise
the risk of rehospitalization. Longer-term, double-blind, randomized,
fixed-dose studies are warranted to better delineate the effectiveness of
different pharmacotherapeutic regimens for the outcomes of patients with major
depressive disorder.